ScienceDaily (Mar. 3, 2008) — Scientists have used a supercomputer to shed new
light on one of the most important theories of physics, the Standard Model,
which encapsulates understanding of all the material that makes up the universe.
This 30-year-old theory explains all the known elementary particles and three of
the four forces acting upon them - however, it excludes the force of gravity,
which is its shortcoming.

Physicists have been trying to find the missing pieces in the jigsaw that would
extend the Standard Model into a complete theory of all the forces of nature.
However, the landmark findings by researchers at the Universities of Edinburgh
and Southampton, and their partners in Japan and the US,
confirm the Standard Model to even
greater precision than before, deepening the puzzle.
The project's enormously complex calculations relate to the behaviour of tiny
particles found in the nuclei of atoms, known as quarks. In order to carry out
these calculations, the researchers first designed and built a supercomputer
that was among the fastest in the world, capable of tens of trillions of
calculations per second. The computations themselves have taken a further three
years to complete.

Their result shows that the Standard Model's claim to be the best theory
invented holds firm. It raises the stakes for the riddle to be solved by
experiments at the Large Hadron Collider at CERN, which will switch on later
this year. Physicists’ efforts to confront Standard Model predictions using the
most powerful computers available with the most precise experiments offer no
clues about what to expect.

Professor Chris Sachrajda of the University of Southampton’s School of Physics
and Astronomy said: ‘Modern supercomputers and improved theoretical techniques
are allowing us to explore the limits of the Standard Model to an unprecedented
precision. The next stage will be to combine such computations with new
experimental results expected from the Large Hadron Collider to unravel the next
level of fundamental physics.’

Professor Richard Kenway of the University of Edinburgh's School of Physics
added: ‘Although the Standard Model has been a fantastic success, there were one
or two dark corners where experimental tests had been inconclusive, because
vital calculations were not accurate enough. We shone a light on one of these,
but to our enormous frustration, nothing was lurking there.’

The research, published in Physical Review Letters, was supported by the Science
and Technology Facilities Council.